METHOD FOR PRODUCING POLYVINYL ALCOHOL RESIN, AND POLYVINYL ALCOHOL RESIN OBTAINED BY THE METHOD

摘要

Provided is a method for producing a polyvinyl alcohol resin, comprising the steps of copolymerizing an aliphatic vinyl ester (A) with diacetone acrylamide (B), at least a part of which diacetone acrylamide (B) is added at a later stage, in the presence of a polymerization catalyst in an alcohol solvent, so that the ratio (a)/(b) of the polymerization yield at the end of the polymerization (a) to the polymerization yield at the end of the later addition (b) of diacetone acrylamide (B) is in the range of 1.01 to 1.10, and saponifying the resulting copolymer.